The present invention relates to a method for measuring electrodes to be exchanged in electrolysis cells, after using up of the electrode surface directed towards the opposed electrode, in which one withdraws from the cell the electrode to be exchanged, and lowers in a new one in its place.
In a known manner, in the electrolysis of aluminium carbon anodes are employed, which in the course of their period of operation burn away more and more. In this connection, firstly the anodes must be continuously newly positioned during their period of use after measurement of the burning away, because it is of the greatest importance that their adjustment of spacing with reference to the aluminium cathode satisfies predetermined criteria. More simply stated, the surfaces of the anodes facing the cathode must be always held at constant spacing with reference to the aluminium cathode. As soon as an anode is completely burnt away, it must be exchanged, while the newly inserted anode must be positioned with reference to the aluminium cathode in the same position as the exchanged one. For this purpose it is usual to provide the old anode with a chalk mark, to place the old and the new anode alongside one another on the floor, and to transfer the measurement marked with the chalk mark on the old anode onto the new one. This procedure is however liable to error, caused by the width of the chalk mark, errors of parallax during the transference of the measurement from the old anode to the new anode, irregularities of the surface on which hey are stood etc. Fundamentally the described customary method strongly depends as regards its precision on subjective measurement errors of the operating personnel as well as on accidental objective errors.